1680915149 has 2 divisors, whose sum is σ = 1680915150. Its totient is φ = 1680915148.

The previous prime is 1680915127. The next prime is 1680915151. The reversal of 1680915149 is 9415190861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1622881225 + 58033924 = 40285^2 + 7618^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1680915149 is a prime.

It is a Sophie Germain prime.

Together with 1680915151, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1680915179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840457574 + 840457575.

It is an arithmetic number, because the mean of its divisors is an integer number (840457575).

Almost surely, 2^1680915149 is an apocalyptic number.

It is an amenable number.

1680915149 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680915149 is an equidigital number, since it uses as much as digits as its factorization.

1680915149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 44.

The square root of 1680915149 is about 40998.9652186491. The cubic root of 1680915149 is about 1189.0002074902. Note that the first 3 decimals are identical.

The spelling of 1680915149 in words is "one billion, six hundred eighty million, nine hundred fifteen thousand, one hundred forty-nine".